Marcello Giagheddu

Microdialysis measurement of cortical and hippocampal acetylcholine release during sleep-wake cycle in freely moving cats

The variations of Acetylcholine (ACh) release in the cerebral cortex and dorsal hippocampus were monitored by microdialysis during the electroencephalographically recorded sleep-waking cycle in freely moving cats. The results show a state-dependent variation in ACh output in both the cortex and the hippocampus. ACh release increased by approximately 100% during quiet waking (QW) and by 175% during active waking (AW) as referred to slow wave sleep (SWS) baseline. In contrast, a clear difference between the two areas was observed during REM sleep. During this stage ACh release in the cortex reached approximately the same values observed during QW, while in the hippocampus ACh release rose to about 4-fold the level obtained during SWS or twice that of QW. The results support the idea that the increase in ACh release in the cortex reflects the desynchronized EEG of wakefulness and REM sleep, while the marked increase of ACh during REM in the hippocampus may be related to the sustained theta activity in this area.

Epidemiologic study of amyotrophic lateral sclerosis in Sardinia, Italy

ABSTRACT From 1957 to 1980 in Sardinia, 182 cases of ALS with a mean annual incidence of 0.51 per 100,000 inhabitants and a prevalence rate of 3.65 per 100,000 inhabitants (prevalence day 21.10.1971) were observed. The disease was found to be more common in males, in subjects aged 50 to 70 years and in farmers and shepherds. Incidence in various areas of the island was found to be different. The common form was more frequent, had earlier onset and greater median survival rate.

Corticotropin-releasing factor (CRF) increases paradoxical sleep (PS) rebound in PS-deprived rats

The intracerebroventricular injection (1 microgram) of murine corticotropin-releasing factor (r-CRF) to rats after 72 h of sleep deprivation markedly postponed the sleep onset, reduced slow wave sleep and prolonged the duration of paradoxical sleep (PS) episodes. Moreover, CRF is-to our knowledge-the first compound to be able to further prolong PS in a condition (sleep deprivation) in which its duration is already increased. Our findings raise the possibility that CRF might play a physiological role in the regulation of the sleep-wakefulness cycle.

Localized Epileptiform Activity Induced by Murine CRF in Rats

Summary: Murine corticotropin releasing factor (rCRF), injected intracerebroventricularly into rats at a dose of 10 |Ag produced increased motor activity, grooming, and recurrent episodes of epileptic activity localized in the hippocampal leads. Such activity persisted for ˜5 h and was characterized by recurrent trains of biphasic spikes never associated with behavioral signs of epilepsy. The intraperitoneal administration of carbamazepine (15 and 30 mg/kg) reduced the epileptic activity for ˜90 and 120 min, respectively, whereas that of naloxone (8 mg/kg) was ineffective. The results suggest that rCRF‐induced spiking activity might be a model of temporal lobe epilepsy.

Comparison of MRI, EEG, EPs and ECD-SPECT in Wilson's disease

Objectives – The purpose of this study is to evaluate the efficiency of a few methodologies in detecting anatomo‐functional brain abnormalities in patients with Wilsons disease. Materials and methods – Twenty‐three patients with Wilsons disease underwent almost simultaneously brain magnetic resonance imaging (MRI), computerized electroencephalography (EEG), multimodal evoked potentials (EPs) and ECD single photon computerized tomography (SPECT) evaluation. The clinical picture was of the neurologic type in 8 patients and of the hepatic type in 15. Results – MRI was abnormal in 7 patients with neurological manifestations. The EPs proved pathologic in 7 neurologically symptomatic patients and in 4 cases with hepatic form. These results agree with those reported in other case studies. The EEG records were abnormal only in 3 cases. Nevertheless, the most interesting finding of this study is the particular frequency (86%) of diffuse or focal decrease of ECD uptake shown by brain SPECT. Conclusion – We highlight the use of this interesting procedure in the therapeutic monitoring of this disease.

Epidemiological study of myasthenia gravis in Sardinia, Italy (1958–1986)

ABSTRACT— From 1.1.1958 to 31.12.1986, 110 cases of MG were observed in Sardinia, with a mean annual incidence of 2.5 × 1,000,000 inhabitants and prevalence rates of 7.5, 17.6, 31.4 and 45.0 × 1,000,000 inhabitants respectively (prevalence days: 15.10.1961,24.10.1971,25.10.1981 and 31.12.1986). The disease was found to be more frequent in women. There were no differences in the distribution of MG in various areas of the island. The muscle group more frequently involved at onset was the ocular. In 6.4% of patients an association with thyroid disorders was observed. The mortality of MG patients was significantly higher than expected. Removal of the thymus, carried out in 58 patients, was shown to be useful in the treatment of the disease, particularly in patients without thymomas. No familial cases were observed.

Sclerosteosis: report of a case in a black African man.

Sclerosteosis is a rare genetic disorder of bone modelling, similar to, but distinct from, van Buchem disease; it has been described almost exclusively in Afrikaners of South Africa, a white population of Dutch ancestry. Isolated cases have been reported in a girl in Japan, a boy in Spain, and in multiracial families in Brazil and USA.

Amyotrophic lateral sclerosis in Sardinia, Italy: an epidemiologic study

The authors carried out an epidemiologic study on amyotrophic lateral sclerosis in Sardinia for the years 1957 through 1990. The duration of the disease and survival were significantly shorter in bulbar form. The distribution of ALS in various areas of the island was found to be not at all homogeneous. Mean yearly incidence showed no significant variations in the decades 1971–80 and 1981–90. In the last decade, an increase of bulbar forms was observed.

Conjugal amyotrophic lateral sclerosis: a report on a couple from Sardinia, Italy.

A conjugal case of amyotrophic lateral sclerosis (ALS) observed in Sardinia, Italy is reported. This is believed to be the ninth such observation described in the literature. The couple had lived together for 38 years in a house adjacent to the distillery they owned. No exogenous factors were revealed which could explain the genesis of the disease in either patients. Particularly, exposure to alcohol does not appear to have been involved in causing ALS. On the basis of statistical and epidemiological evaluations, the most likely explanation is that this association was purely coincidental.

Hippocampal θ activity after systemic administration of a non-peptide δ-opioid agonist in freely-moving rats: relationship to D1 dopamine receptors

Abstract Hippocampal θ activity was acquired and processed off-line from digitized EEG recordings after subcutaneous (s.c.) administration of the non-opioid δ agonist BW 373U86 (0.5–2.5 mg/kg) in freely-moving rats. Relative θ power spectral analysis, implemented by a signal processing software, showed that BW 373U86 induced a dose-dependent increase in the slow component of θ band (Type 2 θ), while movement-related fast θ band (Type 1 θ) failed to show significant changes. Moreover, the increase in relative Type 2 θ power showed a maximal change at 1 mg/kg of BW 373U86, while higher doses, although effective in increasing relative Type 2 θ, induced locomotion and irregularly increased Type 1 hippocampal θ activity. The administration of 10.0 mg/kg of the δ antagonist Naltrindole (NLI) 30 min before BW 373U86, abolished hippocampal Type 2 θ increase. The rise of relative Type 2 θ power induced by BW 373U86 (1–2.5 mg/kg) was greatly attenuated by 0.1 mg/kg of the selective dopamine (DA) D1 antagonist SCH 23390. Administration of 0.1 mg/kg of SCH 23390 alone did not modify hippocampal Type 2 θ. These results indicate that δ receptors modulate the expression of hippocampal Type 2 θ and dopamine, through D1 receptors, exerts a permissive role on this influence.